Check here first: If you updated LimeWire & cannot find your Downloads

2nd option is to search on your computer for .mp3 or whichever is the format of music you normally download, by typing in that extension & selecting each of the search results which will show their location. One of those locations in your search will show your 'old' download location. Sounds like you originally had a custom or different download location but your LW is now choosing a different location.

Also, go to LW's library window, click on Shared, Click Explore button & open that folder, are the files there?